Improve your winter grazing

Stringent slurry regulations and soaring feed and bedding costs mean many livestock producers are trying to make more of their grazing. But winter turnout can cause havoc on wet soils, so what practical steps can farmers take to manage their winter grazing better?

Speaking at a recent event organised by the Catchment Sensitive Farming Delivery Initiative in Somerset, agronomist Simon Draper said the first step was to assess the runoff risk of individual fields. Under cross-compliance measures, farmers were required to do this as part of the Soil Protection Review, but it would help to identify best management practices across the farm.

Farmers should consider soil type, slope and at-risk factors such as watercourses or roads. Flooding or erosion from farmland into roads, watercourses or houses could render the farmer liable under insurance claims, unless they had completed the Soil Protection Review and put in place appropriate measures, he added.

Compaction was a major issue, which resulted in poor grass or crop growth and increased the risk or runoff and erosion. Many grass leys were compacted through previous soil management, trafficking or poaching, and producers should dig test holes in all their fields to identify problem areas. Having dug a hole, they should look for any horizontal cracks in the soil – these would indicate the depth of any compaction.

“Vertical cracks are good, as they enable roots to grow down through the soil structure. But horizontal cracks indicate compaction from ploughing or power harrowing, for example. They will tell you what you need to do in the spring to relieve the compaction,” said Mr Draper. 

Shallow compaction could be alleviated with a sward lifter or aerator; deeper compaction may require ploughing, shakerating or subsoiling. “But never go deeper than 12 inches or you will destroy the structure of the subsoil.”

Puddles of water, poor crop establishment or kinked tap roots in turnips would all indicate compaction, he added. “Think about the preparation of the current crop and the impact it may have on the next crop – it’s all about timeliness of operations.”

Worms in the soil were another good indicator of soil health. “When you are outwintering on grass, the big issue is how much damage you do. There should be 40 earthworms in a good spadeful of soil – if you haven’t got earthworms, you haven’t got good soil structure.” Heavy applications of slurry would also damage worm populations due to ammonia poisoning.

Good infrastructure, in the form of access tracks, water troughs and movable fencing, would all help farmers to make the most of their grassland, said Mr Draper. “Remove stock when it’s wet – they should always have a dry lying area.” Entrances should be at the top of fields, to prevent runoff and erosion, but having multiple entrances was ideal. “Then you can subsoil, plough or cultivate where an entrance is damaged and move onto the next one.”

When feeding stock outside, producers should locate feeders at the bottom of slopes, to prevent mud from being washed down the slope. “Move ring feeders daily, and place large silage bales around the field that you can move to and unwrap each day, to reduce traffic.” Ideally, feeders should be placed next to tracks, and sited in a hexagon-type shape to use in a rotation.

Strip grazing and back fencing allowed grass to regrow and limited poaching, he added. Hardy grass varieties were essential, but alternative crops such as stubble turnips could supplement inadequate grass supply, and could be strip grazed in a similar way.

“When your field is on a long, thin slope, strip graze vertically with the feeders at the bottom – on a shallower slope, start grazing at the bottom of the hill and work upwards.” This would limit runoff from previously poached land.

CSF officer Roy Hayes said the drive to make the most of grassland was particularly relevant, given the impending Nitrate Vulnerable Zone regulations. These would force farmers to look at their slurry production and storage capacity, he said. “Many farmers are now considering their options, and that will no doubt include ways to reduce slurry storage requirements by extending their grazing regimes and even a push towards keeping stock outside throughout the winter months. Careful grassland management will therefore be essential to maximise output and minimise soil damage.”